Composition for injection moulding, part produced from the composition and method for production of the composition

Abstract

A composite composition for injection moulding comprising: an organic matrix, between 5 and 15% in weight of reinforcing fibers, and solid particles comprising more than 5% in weight of beads and fire-resistant mineral particles 50% in weight whereof present a distribution function of equivalent diameters comprising at least two modes. A method for producing 100 parts in weight of the composition comprising: preparation of an organic matrix, adding and mixing of 5 to 15 parts in weight of reinforcing fibers, and adding and mixing of solid particles comprising fire-resistant mineral particles and more than 5 parts in weight of beads. A part obtained by injection and by moulding of the composition.

1 . Composite composition for injection moulding comprising:
 from 15 to 50% in weight of an organic matrix comprising a thermosetting resin,   reinforcing fibers, and   solid particles comprising fire-resistant mineral particles,   
     wherein the quantity of reinforcing fibers is comprised between 5 and 15% in weight of said composition, at least a portion of the solid particles greater than 5% in weight of said composition comprises beads, and at least 50% in weight of the fire-resistant mineral particles present a distribution function of the equivalent diameters comprising at least two modes. 
   
   
       2 . Composition according to  claim 1 , wherein the beads have a form factor of less than 2. 
   
   
       3 . Composition according to  claim 2 , wherein the beads have a substantially spherical shape. 
   
   
       4 . Composition according to  claim 1 , wherein the beads are made of glass. 
   
   
       5 . Composition according to  claim 1 , wherein a reinforcing fiber comprises a plurality of filaments. 
   
   
       6 . Composition according to  claim 5 , wherein the beads have a diameter comprised between 0.3 and 5 times the mean diameter of the filaments. 
   
   
       7 . Composition according to  claim 5 , wherein at least 90% in weight of the solid particles present an equivalent diameter comprised between 0.05 and 5 times the mean diameter of the filaments of the reinforcing fibers. 
   
   
       8 . Composition according to  claim 7 , wherein the median of the cumulative granulometric distribution function, corresponding to the fiftieth percentile in weight of the solid particles, is comprised between 0.2 and 20 times the mean diameter of the filaments of the reinforcing fibers. 
   
   
       9 . Composition according to  claim 7 , wherein at least 50% in weight of the solid particles present a distribution function of the equivalent diameters comprising at least three modes. 
   
   
       10 . Composition according to  claim 5 , wherein at least 90% in weight of the fire-resistant mineral particles present a mean equivalent diameter comprised between 0.05 and 5 times the mean diameter of the filaments of the reinforcing fibers. 
   
   
       11 . Composition according to  claim 8 , wherein the median of the cumulative granulometric distribution function, corresponding to the fiftieth percentile in weight of the fire-resistant mineral particles, is comprised between 0.1 and 2.0 times the mean diameter of the filaments of the reinforcing fibers. 
   
   
       12 . Composition according to  claim 1 , wherein the fire-resistant mineral particles are essentially formed by hydrated aluminas. 
   
   
       13 . Composition according to  claim 1 , wherein the fire-resistant mineral particles have different shapes. 
   
   
       14 . Composition according to  claim 1 , wherein the organic matrix comprises a thermoplastic additive. 
   
   
       15 . Method for production of 100 parts in weight of a composition by injection moulding comprising:
 preparation of at least a part of an organic matrix by mixing compounds comprising a thermosetting resin,   adding and mixing reinforcing fibers, and   adding and mixing solid particles comprising fire-resistant mineral particles,   
     wherein the quantity of added and mixed reinforcing fibers is comprised between 5 and 15 parts in weight of said composition, a portion of the added and mixed solid particles comprises at least 5 parts in weight of beads, and at least 50% in weight of the fire-resistant mineral particles present a distribution function of the equivalent diameters comprising at least two modes. 
   
   
       16 . Method according to  claim 15 , wherein adding and mixing of the beads and of the reinforcing fibers are performed substantially at the same time. 
   
   
       17 . Method according to  claim 15 , wherein another part of the organic matrix comprising a coupling size agent is added substantially together with the fire-resistant mineral particles. 
   
   
       18 . Method according to  claim 15 , wherein adding and mixing of the beads are performed keeping the temperature of the composition at a substantially constant value. 
   
   
       19 . Part obtained by injection moulding of a composition, wherein said composition is a composite composition according to  claim 1 , the shape of the part being defined by the shape of the mould in which said composition is injected.